This application claims the priority of German Patent Application No. 101 40 304.6 filed on Aug. 16, 2001, the disclosure of which is being incorporated herein by reference.
The invention relates to a device on a carding machine for cotton, synthetic fibers and the like. More particularly, the invention relates to flat bars with clothing, wherein the flat bars are positioned opposite clothing mounted on a roller, such as, for example, a main carding cylinder.
The flat bar of the device shown in U.S. Pat. No. 3,151,362 has a back piece and a support body with an underside. A clothing strip is attached to the underside and extends in a longitudinal direction of the flat bar. The clothing strip has a support element with several textile layers having a plurality of wire hooks embedded therein. The clothing strip is attached with at least two clamps extending over the longitudinal sides of the support body. With one end, the clamps encircle the edge regions of the clothing strip in the longitudinal direction while they engage with the other end in recesses of the support body. In practical operations, the clamps are fashioned from sheet-metal strips, one longitudinal edge of which is pushed into the textile material. During assembly, the textile material of the clothing strip is attached with considerable tension and form-fitted to the support body of the flat bar. In the process, the clamps exert tensile forces, such that the textile material is spherically deformed away from the flat bar underside. This results in the clothing wire points being arranged in an undesirable manner pointing outward on a convex enveloping curve. A set of such flat bars has a height fluctuation of, for example, 0.05 mm when not in use. When in use, however, the height differences can increase to approximately 0.2 mm. Re-sharpening the clothing point on the machine only results in an insignificant improvement of the accuracy. Following a throughput of approximately 400 tons of fiber material, the flat bar clothing is worn out to the point that it must be replaced. To dismantle the sheet metal straps, the flat bar is clamped down and the form-fitting connection is reversed with the aid of a lever and pliers. The considerable forces required during the assembly and dismantling negatively affect the dimensional stability of the flat bar. Undesirable production tolerances for the flat bar body compound these dimensional inaccuracies. As a result of the aforementioned disadvantages, the clothing wire points of the clothed flat bar must be leveled by grinding them down.
Modern flat bars are made of aluminum and are extruded. During practical operations, the extruded flat bar is then cut to size and is leveled, for example to within 0.05 mm of flat. Support pins are subsequently glued into openings on the side of the support body, over a partial region in a tolerance-free plane. Height fluctuations for the glued-in pins result due to the extrusion process and the leveling operation. To keep the height difference for a flat bar set to within 0.05 mm of each other, the bars are sorted according to their height following pin gluing. This operation is time consuming. The clothing strip is then mounted to the underside of the flat bar in the above-described manner. The total height difference when adding the tolerances of the flat bar, the flat bar clothing, the offset during assembly, and the deformation caused by tensioning when mounting the clothing is significant. As a result, the previously described leveling grinding is carried out across all the flat bars after assembly. In the process, up to 0.15 mm is ground off, thus reducing the technological effectiveness of the ground-down, clothing wire points. During the grinding-down operation, the actual operational precision in the region of the wire points is removed from the clothing wire. The addition of the tolerances during the assembly of the flat bar clothing, the technologically damaging leveling grinding, and wear during use represent particular disadvantages in these machines.
Thus, it is an object of particular embodiments of the invention to create a device of the aforementioned type that avoids the above-mentioned disadvantages and, in particular, allows for an easy production of an inherently stable flat bar with clothing.
Embodiments of the invention include a flat bar assembly for use with a carding machine having a carding cylinder, the carding cylinder having clothing. The assembly has a flat bar, flat bar clothing attached to the flat bar, and an equalizing layer between the flat bar and the flat bar clothing. The flat bar clothing is for positioning opposite the carding cylinder clothing, and the equalizing layer fills a space between the flat bar and the flat bar clothing to compensate for distance differences between the flat bar clothing and the flat bar and to locate the flat bar clothing at a predetermined position relative to the flat bar.
An inherently stable flat bar can be produced easily by arranging an equalizing layer between the flat bar and the flat bar clothing to compensate for differences in the distance between the two. All production tolerances of the flat bar, the clothing and those occurring during the assembly (including the dismantling) are compensated for. The clothed flat bar according to the invention advantageously avoids the addition of tolerances resulting from the assembly and dismantling of the flat bar clothing, the technologically damaging leveling grinding and uneven wear during use.
The equalizing layer advantageously equalizes the distance differences between the rear surface of the clothing and the underside of the flat bar. The equalizing layer can preferably locally equalize distance differences between the rear surface and the underside. The flat bar forms a component of a set of traveling flats and is locally secured. A flexible clothing is provided and preferably comprises a support and clothing wire points, wires, hooks or the like. The support is strip-shaped and the clothing preferably consists of sawtooth wire strips, e.g. all-steel clothing. The clothing is attached in the region of the flat bar underside and is preferably glued to the flat bar. The equalizing layer preferably consists of a synthetic material or the like. This equalizing material can be a synthetic resin, such as epoxy resin. Polyester or a similar material is preferred for the equalizing material. The synthetic material, the synthetic resin, or the like should harden and should preferably be pourable. It is furthermore useful if the synthetic material, the synthetic resin, or the like, is adhering and preferably adheres more to the clothing support than to the underside of the flat bar. An adhesive layer can be provided between the equalizing layer and the underside of the flat bar, preferably in the form of an adhesive foil. It is useful if at least one side of the adhesive foil is sticky. The equalizing layer or the adhesive can be detachable and should preferably be water-soluble. A soluble lacquer or the like is preferably provided for the equalizing layer and the adhesive. Preferably, the equalizing layer and the adhesive can be removed without residue from the underside of the flat bar. The underside of the flat bar is preferably provided with an equalizing step. The flat bar and the flat bar clothing can be aligned to the same reference plane, preferably a plane across the tips of the flat bar clothing. It is useful if the flat bar is an extruded profile made of a lightweight metal, e.g. aluminum, and is preferably a hollow profile. The correct length of the flat bar is cut and then preferably leveled. Two end parts (flat bar heads) are preferably aligned at the ends to the support body. These two end parts are preferably pins, made of hardened steel or a similar material, which are fastened in recesses of the support body. The support element (textile material) and the equalizing layer are preferably arranged in a recess on the underside of the flat bar and/or on the support body. The recess can be delimited by at least two ridges along the longitudinal sides of the support body. The support body preferably has inlet openings, e.g. through bores, for filling in the equalizing layer material. It is advantageous if the distance between sliding surfaces of the flat bar heads and a curve defined by the flat bar clothing wire points is the same.
An apparatus to assist the assembly of the flat bar assemblies has a flat plate and a bearing element. The plate is preferably a magnetic plate. The flat bar heads rest on a reference plane, and the plate and the reference plane are preferably attached to the bearing element. Two reference planes are oriented parallel to each other and the distance between these reference planes should be adjustable. It is advantageous if the flat bar clothing points rest on one reference plane, the flat bar heads on the other reference plane and the intermediate layer is inserted between the support body and the clothing strip. An adhesive strip is preferably inserted between the intermediate layer and the underside of the support body. The adhesive strip is preferably sticky on two sides. The support element preferably has at least one fastening plate, for example of metal, which is attached with a screw or the like to the flat bar. The adhesive strip preferably has a shackle or the like. The width of the adhesive strip and the adhesive equalizing layer is preferably wider than the width of the support body, the equalizing layer and/or the support element.